We have developed an improved method for analysis of the calibration curves which arise in agarose and polyacrylamide gel electrophoresis of linear duplex DNA fragments using continuous or pulsed-field conditions. We employ a "four parameter logistic" model, which introduces one more parameter than was used previously in a rectangular hyperbola model. This method provides better goodness of fit, better precision, and reduced bias. The method is widely applicable, especially in studies of physical mapping of the human genome and genetic linkage analysis. A new program, DNAFIT, has been developed to implement this method for routine analysis with semi-automated methods involving digitizing tablets. The method provides improved quality control for routine laboratory analyses and also facilitate choice of optimal gel concentration for a desired molecular weight range. We have developed improved methods for detection and characterization of episodic hormone secretion, and to estimate the instantaneous rate of hormone secretion using deconvolution analysis. These methods have been applied to several clinical investigations of the dynamics of LH, FSH, prolactin, ACTH, cortisol, and beta-endorphin. New methods have been developed to evaluate coincidence of pulses in two hormonal time series. These include the concept of "specific concordance" as a function of threshold levels and adjustable lag times, and also uses the Kappa statistic.